Enhanced removal and detection of benzo[a]pyrene in environmental water samples using carbon dots-modified magnetic nanocomposites

Abstract Magnetic nanoparticles (MNPs) have already proven their efficacy in the disposal of a wide array of environmental contaminants in recent years. However, the difficulties in dispersibility and agglomeration of MNPs arising from its own physical and chemical properties limit its large-scale application. Herein, we fabricated the carbon dots/fatty acid-coated MNPs (CDs/C 11 -Fe 3 O 4 ) through a facile and simple method. To utilize the advantage of carbon dots, these limitations can be mitigated by diminishing the size of MNPs and modifying the surface of MNPs. Detailed characterization including VSM, FT-IR, XPS and TEM conformed that the higher adsorption capacity of CDs/C 11 -Fe 3 O 4 is mainly attributed to low average size ( 11 -Fe 3 O 4 (about 13 nm). The CDs/C 11 -Fe 3 O 4 showed higher adsorption performance than that of C 11 -Fe 3 O 4 nanocomposites (76.23 ng mg −1 for CDs/C 11 -Fe 3 O 4 and 59.89 ng mg −1 for C 11 -Fe 3 O 4 ). The adsorption processes of BaP on both C 11 -Fe 3 O 4 and CDs/C 11 -Fe 3 O 4 nanocomposites are exothermic, and well simulated by pseudo-second-order model. Moreover, the CDs/C 11 -Fe 3 O 4 were also applied for the detection of BaP in large-volume water samples, which satisfies the China environmental protection standard, are promising candidates for water remediation.